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AES E-Library

Dolby B-Type Noise Reduction for FM Broadcasts

Experiments were carried out recently to test the effectiveness of the Dolby B-type noise reduction system in reducing the noise of FM transmissions, particularly for stereo reception where the operation of the multiplex decoder degrades the signal to noise ratio by 23 dB. Test results, which will be described in the paper, show that the system is effective in reducing this noise as well as other forms of high frequency interference such as SCA -monkey chatter.- The 10 dB noise reduction can be equated to an increase of ten times in transmitter power, or a three times increase in service area.